Exactly. Which I have tried to explain (unsuccessfully, alas) too many times. We only answer calls from numbers we recognize.
This has caused some interesting issues, though. My wife answered one of the unknown-callers on her cellphone anyway, and it turned out to be from her doctor's office. Who couldn't (or wouldn't) explain why the clerk was using per personal cellphone to call patients, or how they got the number. We still maintain a land line, and only eight individuals have my cellular number, only five have hers. Yet somewhere a dataset was purchased, and both our cellular numbers have propagated throughout the Electronic Medical Records system, often as the only contact number.
This has caused some interesting issues, though. My wife answered one of the unknown-callers on her cellphone anyway, and it turned out to be from her doctor's office. Who couldn't (or wouldn't) explain why the clerk was using per personal cellphone to call patients, or how they got the number. We still maintain a land line, and only eight individuals have my cellular number, only five have hers. Yet somewhere a dataset was purchased, and both our cellular numbers have propagated throughout the Electronic Medical Records system, often as the only contact number.